1. Field of the Invention
The present invention relates to a RFID tag which can be used both for Near Field (NF) Radio Frequency Identification (RFID)-type communication and Far Field (FF) RFID-type communication, and more particularly, to a RFID tag which includes an additional antenna for NF RFID communication and FF RFID communication in a single RFID tag, thereby enabling both types of communications.
2. Background of the Invention
RFID is a technology for providing a contactless automatic identification method that an RFID tag is attached to an object for identification so as to automatically identify the object by using radio signals while carrying out communications with an RFID reader through transceive using the radio signals. The RFID technology can supplement the shortcomings of barcode and optical character recognition technologies which are conventional automatic identification technologies.
Recently, the RFID tag is used in several applications, such as a logistic management system, a user certification system, an electronic money system, and a traffic system.
For example, in the logistic management system, freight is classified or inventory control is performed by using Integrated Circuit (IC) tags in which data is recorded instead of delivery slips or tags. Further, in the user certification system, the entrance management is performed by using an IC card in which personal information is recorded.
In general, non-volatile ferroelectric memory can be used for the RFID tag.
Non-volatile ferroelectric memory, that is, Ferroelectric Random Access Memory (FeRAM) has been in the spotlight as a next-generation memory device as it has a data processing speed comparable to that of Dynamic Random Access Memory (DRAM) and retains its data even after when power is turned off.
FeRAM devices have almost the same structure as that of to DRAMs. FeRAMs use ferroelectric capacitors as storage elements. FeRAMs exhibit a high residual polarization property and can retain data even though an applied electric field might be removed.
RFID uses several frequency bands and has different characteristics according to the frequency bands.
In general, when the RFID frequency band is low, the RFID device is likely to exhibit a slow recognition speed, operate in a short range, and is less influenced by extraneous environmental interference. On the other hand, when the RFID frequency band is high, the RFID device is likely to exhibit a fast recognition speed, operate in a longer range and is prone to extraneous interference from the environment.
Conventional RFID tags are divided into an RFID tag used in a low frequency band and an RFID tag used in a high frequency band. That is, an RFID tag equipped with an antenna enabling communication in a low frequency band and an RFID tag equipped with an antenna enabling communication in a high frequency band separately exist. Accordingly, there is a problem in that different RFID tags should be used according to the particular purpose of use.